X-linked Adrenoleukodystrophy

X-linked adrenoleukodystrophy (X-ALD) is the most frequent peroxisomal disorder. Hallmarks are increased levels of plasma very long-chain fatty acids (VLCFA), mutations in the ABCD1 gene, impaired function of ALD-protein and, consequently, decreased import of VLCFA-CoA esters in peroxisomes and VLCFA beta-oxidation. Cerebral demyelination and axonal degeneration of the spinal cord are the main causes of neurological deficits. Endocrine dysfunction, particularly adrenocortical insufficiency, is very frequent. Based upon the age of onset of symptoms and the organs most severely affected, several phenotypes can be distinguished. Adrenomyeloneuropathy (AMN) and childhood cerebral adrenoleukodystrophy (CCALD) are the most frequent variants. At least 80% of female carriers will eventually develop neurological symptoms similar to men with AMN. The thin and scanty scalp hair in affected men may facilitate diagnosis of X-ALD. Identification of patients is of utmost importance, as adrenocortical insufficiency can be treated, rapidly progressive cerebral demyelination can be halted, and prenatal diagnostic testing is available. Furthermore, symptomatic therapies and multidisciplinary support may help patients coping with this disease.